Combination count-down counter and reset counter for a duplicating machine or the like

ABSTRACT

Manual operation of a quantity selector knob rotates a selector wheel carrying a stop thereon. An indexing wheel is mounted in adjacent coaxial relationship with the selector wheel and is indexed in one rotary direction in response to cyclical operation of a component of a duplicating machine. The indexing wheel carries a formation for abutting engagement with said stop. Biasing means engage the indexing wheel for urging the latter in a direction opposite said one direction thereby to bring said formation into engagement with said stop. The indexing wheel operates means for deactuating the cyclical operation of the aforesaid machine component when the indexing wheel occupies a predetermined rotary position. In the reset mode of operation, restraining means prevent rotation of the selector wheel during rotation of the indexing wheel in said one direction; in the count-down mode of operation, the force of the restraining means is overcome by frictional engagement between the indexing wheel and the selector wheel thereby causing the latter and the selector knob to rotate with the indexing wheel in said one direction.

United States Patent 1 Fowlie May 8, 1973 Primary Examiner-Stephen J. Tomsky Att0meyMcDougall, Hersh & Scott 57 ABSTRACT Manual operation of a quantity selector knob rotates a selector wheel carrying a stop thereon. An indexing wheel is mounted in adjacent coaxial relationship with the selector wheel and is indexed in one rotary direction in response to cyclical operation of a component of a duplicating machine. The indexing wheel carries a formation for abutting engagement with said stop. Biasing means engage the indexing wheel for urging the latter in a direction opposite said one direction thereby to bring said formation into engagement with said stop. The indexing wheel operates means for deactuating the cyclical operation of the aforesaid machine component when the indexing wheel occupies a predetermined rotary position. In the reset mode of operation, restraining means prevent rotation of the selector wheel during rotation of the indexing wheel in said one direction; in the countdown mode of operation, the force of the restraining means is overcome by frictional engagement between the indexing wheel and the selector wheel thereby causing the latter and the selector knob to rotate with the indexing wheel in said one direction.

14 Claims, 5 Drawing Figures PATENTEDHAY 8191a SHEET 1 BF 2 //v VENTOP Wallace Qfbwlie COMBINATION COUNT-DOWN COUNTER AND RESET COUNTER FOR A DUPLICATING MACHINE OR THE LIKE BACKGROUND OF THE INVENTION 1. Field of the Invention The field of the present invention relates primarily, although not exclusively, to duplicating machines, copying machines, or the like, and in particular to mechanism for counting the cycles of operation of a component of such machines, such as a scanner or paper feeder, for example. As is known to those skilled in the art, it is desirable to provide such machines with a counting mechanism which will deactuate the machine after a preset number of copies have been made.

2. The Prior Art It is known to provide such machines with so-called count-down counters or mechanism which count down from a preset number and deactuate some component of the machine after the preset number of copies have been made. In using such a counting mechanism, if it is desired to make the same number of copies of several pieces of original material successively, it is necessary to reset the counting mechanism to the preset number after each piece of original material has been copied or duplicated to provide the preset quantity of copies.

It is also known to provide counters of the type shown in Koijumi U.S. Pat. No. 3,456,515 which will count a preset number successively in response to repeated actuation of some component of the associated machine, such as a starting button, for example.

SUMMARY AND OBJECTS OF THE INVENTION The present invention may be-summarized as relating to a counting mechanism operable in one mode to act as a count-down counter for deactuating a component of the duplicating machine or the like after a preset number of copies have been made and operable in a second mode such that after the preset number of copies have been made and the cyclical component of the machine has been deactuated, the mechanism will be ready to count the preset number through successive sequences without resetting the preset number or making any other adjustment to the counting mechanism.

It is a primary object of the present invention to provide a new and improved mechanism alternately operable as a count-down counter and as a reset counter.

Another object of the present invention is to provide a new and improved mechanism of the type described, which mechanism includes a selector wheel and an indexing wheel, the selector wheel and the indexing wheel being rotated together in the count-down mode of operation, the selector wheel remaining stationary and only the indexing wheel rotating in the reset mode of operation.

Still another object of the present invention is the provision of a new and improved mechanism according to the foregoing object wherein restraining means are associated with the selector wheel, and wherein controllable biasing means urge the indexing wheel and the selector wheel into frictional engagement with each other, so that in the countdown mode of operation such frictional engagement causes rotation of the selector wheel and so that in the reset mode of operation the force of such frictional engagement is reduced whereupon the restraining means prevents rotation of the selector wheel.

These and other objects and advantages of the present invention will becomeapparent from the following specification disclosing a preferred embodiment shown in the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view of the counting mechanism according to the present invention;

FIG. 2 is another isometric view of the mechanism shown in FIG. 1, with a portion of a bracket plate being broken away for better illustration of the indexing wheel and the selector wheel;

FIG. 3 is an exploded isometric view of the indexing wheel, the selector wheel and the shaft mounting these two members;

FIG. 4 is an exploded isometric view showing the principal components of the counting mechanism; and

FIG. 5 is a partial section taken along the line 55 of FIG. 1.

DESCRIPTION OF A PREFERRED EMBODIMENT The counting mechanism of the present invention is embodied within a subassembly, generally designated 10. By way of example, but not by way of limitation, thisv subassembly may form part of an electrophotographic duplicator of the type shown in Suzuki-ct al. U.S. Pat. No. 3,533,691. The subassembly 10 mounts a print button 11, a quantity knob 12, a mode selector control 14 and an exposure adjusting shaft 15. This exposure adjusting shaft and a cam member 16 carried thereby form no part of the present invention and will not be referred to again herein; reference may be had to the aforementioned Suzuki et al. patent for an understanding of the operation of these members.

The subassembly 10 includes a face bracket 18 and a right angle bracket 19, which brackets are suitably mounted in spaced relationship and have aligned openings 20, 21, respectively, receiving a shaft 22, the outer end of which shaft mounts the quantity knob 12. The opening 20 receives an externally threaded sleeve 23 which defines a journal for the shaft 22. i

A selector wheel 24 is mounted on the shaft 22 for rotation therewith. The selector wheel has peripherally arranged detent formations 25 preferably corresponding in number to the numerical indicia formed on the quantity knob 12. It will be understood that manual rotation of the quantity knob 12 imparts corresponding rotation to the selector wheel 24. As noted in FIG. 5, a detent plunger 27 has a stem portion 28, such plunger being mounted for reciprocal sliding movement in aligned apertures formed in a U-shaped bracket 29. This bracket is suitably secured to the face bracket 18. A spring 30 encircling the stem portion 28 has one end in abutting engagement with one leg of the bracket 29 and its other end abutting the shoulder formed by the juncture of the plunger 27 and the stem portion 28 for urging the plunger into yieldable detenting engagement with the formations 25 on the selector wheel 24.

As noted in FIG. 3, the selector wheel includes an annular cavity 32 interrupted by a radially extending stop bar 33. Referring to FIGS. 4 and 5, it is seen that the selector wheel 24 includes another radially extending rib 35; this rib is arranged to abut a pin 36 mounted on the face plate l8for limiting rotation of the shaft 22 and the quantity knob 12 in a clockwise direction as a maximum number to be counted.

A bushing 38 is mounted on the shaft 22 adjacent the selector wheel 24; this bushing mounts a torsion spring 39. As seen in FIG. 3, one end 39a of the torsion spring is bent so as to engage the radially extending stop 33. The other end 39b of the torsion spring is bent so as to be received within an aperture 40 formed in an indexing wheel 42. This indexing wheel is mounted on the shaft 22 for rotation relative thereto. The torsion spring 39 acts to urge the indexing wheel counterclockwise as viewed in FIG. 3.

The indexing wheel 42 includes an abutment formation 43 on the face thereof adjacent the selector wheel 24. When the indexing wheel 42 is rotated under the influence of the torsion spring 39, the formation 43 is brought into abutting engagement with the stop 33 on the selector wheel 24 establishing the limit of such rotation of the indexing wheel. The indexing wheel carries an integral annular formation 45 defining a series of ratchet teeth 46. It is noted that the indexing wheel includes a peripheral recess or notch 47. At this time it should be mentioned that the indexing wheel includes an annular surface 48 which frictionally engages an annular-surface 49 on the selector wheel 24.

A yoke 50 includes a bore 51 pivotally receiving a pin (not shown) supported from the angle bracket 19. The yoke 50 has a first leg 50a mounting a pin 52 engaged by one end of a spring 53. The other end of this spring is anchored to a pin 54 (FIG. 2) mounted from the bracket plate 19. The yoke 50 includes another leg 50b suitably supporting a cam roller 56. This cam roller is engaged by the inclined cam surface 57a of -a camming bar 57 forming a part of a scanning mechanism, for example, such mechanism constituting a cyclically operating component of a duplicating or copying machine. It will be understood that the member 57 is reciprocated or cycled during operation a of the machine and it will be apparent that such movement in cooperation with the spring 53 imparts rocking movement to the yoke 50.

The yoke 50 includes a third leg 50c mounting a pin 58; this pin is received within a bore 59 of a pawl 68. One end of such pawl has an opening 61 in which is received a pin 61a (FIG. 2) engaged by one end of a spring 62; the other end of this spring is anchored to the pin 54. A pawl guide plate 63 is appropriately secured to the bracket plate 19 adjacent an opening 65 therein. This guide plate has a formation 63a which is engaged by a follower surface 66 on the pawl 60.

The interengagement of the surfaces 63a, 66, causes the guide pawl 60 to be disengaged from the ratchet teeth 46 during the return stroke of the pawl. The pawl 60 is caused to move in the forward or ratcheting direction by the rocking action of the yoke 50, such movement being imparted to the latter by reciprocating movement of the member 57. The indexing wheel is indexed or stepped in a clockwise direction (FIG. 3) in response to engagement between the ratchet teeth 46 and the pawl 60. 1

An actuating arm 68 includes an aperture 69 receiving a fastener 70, which fastener is mounted in an aperture 71 in the face bracket 18. It is apparent the fastener mounts the actuating arm 68 for pivoting movement.

The actuating arm 68 includes an integral, generally vertically disposed flange 78 which engages an actuating member (not shown) of a microswitch 79. The actuating arm includes a generally right angle bent end portion 80 supporting the print or actuating button 11. This end portion 80 of the actuating arm also carries a pin 82, which pin is adapted to be received within the recess 47 of the indexing wheel as best seen in FIG. 2.

The actuating arm 68 includes an aperture 83 receiving a fastener 84, which fastener is received in an aperture 85 of a plate 86. It will be apparent that the plate 86 is mounted for pivoting movement relative to the actuating arm about the fastener 84. A spring 88 has one end thereof engaged with a pin 89 mounted on the plate 86 and the other end thereof engaged with a pin 90 mounted on the actuating arm 68. The plage 86 includes a generally vertically disposed flange 92 which engages the actuating members 93, 94 (FIG. 2) of a pair of microswitches 95, 96', respectively. It is apparent that the spring 88 biases the plate 86 in a direction such that the flange 92 is urged into engagement with the microswitch actuating members 93, 95.

By way of example, in one duplicating machine in which the present invention may be embodied, the switch 79 is a momentary switch which is arranged to close an associated relay for initiating the printing cycle of the machine and comes into play only when a single copy is to be made. The switch 95 comes into play to operate the various components of the machine in the proper sequence when multiple copies are to be made. In the particular machine being referred to by way of example, the switch 96 was not used.

The face bracket 18 includes an aperture 97 supporting a fastener 98 which is received in a bore 99 of a bell crank 1011 thereby pivotally mounting the latter. One

arm 109a of the bell crank supports an upstanding'pin 101 engaged by one end of a coil spring 102. The other end of the spring 102 is engaged with a pin 103, the latter being mounted on the actuating arm 68. It is apparent that the spring 102 urges the actuating arm 68 in a counterclockwise direction (looking downwardly) about the pin 70; movement of the actuating arm in this direction is limited by engagement of an actuating arm formation 104 with a stop (not shown).

The other arm 1110b of the bell crank mounts an upstanding pin 105 received within an aperture 106 formed in one end of a rod 107; the other end of this rod mounts the selector control button 14. The pin 105 is also engaged by one end of an overcenter snap-type spring wire 109, the other end of such spring being engaged by a pin supported by the right angle bracket pivoting movement of the bell crank 100 and to cooperate with the spring 109 for releasably holding the bell crank in each of its two positions as determined by actuation of the knob 14.

OPERATION OF THE PREFERRED EMBODIMENT Assume that it is desired to operate the counter in the count down mode. The selector button 14 is pushed inwardly bringing the bell crank arm Gb into engagement with the stop 113 and thereby establishing a predetermined tension on the spring 102. Now assume it is desired to make six copies of a particular piece of original material. Accordingly, the quantity knob 12 is rotated counterclockwise until the numeral 6 on such knob is located at the 12 oclock position (a suitable reference mark is preferably provided on the housing of the counter to facilitate rotation of the knob 12 to its position for establishing the preset number). The aforedescribed movement of the knob 12 causes corresponding movement to the selector wheel 24 thereby establishing a predetermined spatial position for the stop 33 the indexing wheel 42 will not be allowed to move at this time since the pin 82 is received within the recess 47.

Now, the print button 1 1 is depressed causing swinging movement of the actuating arm 68 in a counterclockwise direction about the fastener 70. Such movement of the actuating arm causes the pin 82 to be disengaged from the recess 47 in the indexing wheel 42 whereupon the torsion spring 39 will cause the indexing wheel to rotate counterclockwise (FIG. 3) bringing the formation 43 in abutting engagement with the stop 33. Therefore, the indexing wheel 42 has been spring biased to a predetermined rotary position as determined by the position of the stop 33. The aforedescribed clockwise movement of the actuating arm 68 also causes the three microswitches 79, 95 and 96 to be actuated by reason of the flanges 78, 92 engaging the actuating members of such microswitches. As

- mentioned above, these microswitches may energize various components and/or mechanisms of the duplicating or copying machine.

When the print button 11 is released by the operator, the spring 102 will cause partial return (counterclockwise) movement of the actuating arm 68, movement of the actuating arm in this direction being limited by engagement of the pin 82 with the rear face of the indexing wheel 42. This partial return movement of the actuating arm releases the microswitch 79. Mechanism, such as scanning mechanism, for example, will now be in operation because of the aforementioned actuation of the microswitches, thereby causing horizontal reciprocal movement to the member 57 which in turn imparts rocking movement to the yoke 50. This movement of the yoke 50 in turn operates the pawl 60 for indexing or stepping the indexing wheel in a clockwise direction (FIG. 3). Preferably, the indexing wheel is indexed or stepped an arcuate distance represented by one indexing tooth 46 for each cycle of movement of the component of the machine which is to be counted. In the example under discussion, the indexing wheel will be stepped six times representing the six copies to be made of the original material.

As the indexing wheel 42 is indexed as described, the frictional engagement between the surface 48 thereon and the surface 49 on the selector wheel (resulting from the pin 82 engaging the rear face of the indexing wheel) under the influence of the spring 102 will cause the selector wheel to be rotated with the indexing wheel. In other words, this frictional engagement develops a force sufficient to overcome the restraining force constituted by the spring 30 biasing the detent plunger 28 into engagement with the detent formations 25. Such movement of the selector wheel causes corresponding rotation of the knob 12 thereby counting down the number of copies as they are being made. When the indexing wheel is rotated such that the recess 47 is in a position to receive the pin 82, the latter will snap into the recess under the influence of the spring 102 thereby stopping movement of both the indexing wheel and the selector wheel and returning the actuating arm 68 to its original position releasing the other two microswitches 95, 96 for deactuating the cyclically operated components of the machine, such as a scanner and paper feed, by way of illustration.

Now assume it is desired to make six copies each of several pieces of original material and assume that the operator does not desire to reposition the knob 12 after each piece of original material has been copied the desired number of times. The mode control button 14 is now pulled to the reset position causing the bell crank arm limb to be brought into engagement with the pin 112 and thereby resulting in a reduction in the biasing force applied to the actuating arm 68 by the spring 102. Again, the knob 12 is rotated for presetting the number 6 causing corresponding movement of the selector wheel 24 and thereby establishing a predetermined spatial position for the stop 33. The print button is depressed disengaging the pin 82 from the recess 3-7 and allowing the torsion spring 39 to snap the indexing wheel 42 until the formation 43 comes into abutting engagement with the stop 33. The print button is released as described above and again the indexing wheel 42 is stepped or indexed in a clockwise direction (FIG. 3). However, by reason of the reduced biasing force on the arm 68, which in turn reduces the frictional engagement between the surfaces 48, 49 since the axial force applied to the indexing wheel 42 from the pin $2 is lessened, the selector wheel 24 now remains stationary by reason of the restraining means constituted by the spring biased plunger 27. Accordingly, the knob 12 will be held stationary with the number 6 remaining in the selected position.

After the six copies have been made, the pin 82 will again be received in the recess 47 for stopping the indexing wheel 42 and deactuating the cyclically operated components of the associated duplicating or copying machine. The next piece of original material is mounted in place for copying, and the print button isactuated again. Since the selector wheel 24 has not moved, the stop 33 will be in the predetermined spatial location to arrest rotation of the indexing wheel 42 under the influence of the spring 39 to establish a rotary position of the indexing wheel so as to count the preset number of copies, viz. six. Accordingly, it is seen that in the reset mode of operation, the quantity knob 12 remains stationary and that the preset number will be automatically counted through successive sequences by operation of the actuating or print button 1 1 only.

I claim:

1. Mechanism for counting the cycles of operation of a component of a duplicating machine orthe like, which mechanism is alternately operable in a first mode to count to a minimum number from a preset number and in a second mode to count the preset number through successive counting sequences, said mechanism comprising:

a. indexing means including a member which is indexed in one direction of movement in response to cyclical operation of said component and which cooperates with other means to deactuate such component when said member occupies a predetermined position;

quantity selection means including manually operated means carrying a stop for presetting any one of a quantity of numbers and for substantially simultaneously establishing corresponding respective spatial positions of said stop which is adapted to be engaged by said member for limiting movement of the latter in a direction opposite said one direction;

0. means for actuating said component and for substantially simultaneously causing movement of said member in said other direction for bringing the latter into engagement with said stop; and

. mode control means connected with said selection means operable in one mode for causing movement of said stop in response to movement of said member in said one direction and operable in another mode for preventing movement of said stop during movement of said member in said one direction.

2. The mechanism according to claim 1' further defined by:

a. said selection means including an element carrying said stop and frictionally engaged by said member; said control means including restraining means engaged with said element; and

c. said control means also including means for varying the frictional engagement between said member and said element such that in said first mode the frictional engagement between said member and said element is sufficient to cause movement of the latter upon movement of the former in said one direction and such that in said second mode the frictional engagement between said member and said element is insufficient to cause movement of the latter upon movement of the former in said one direction.

3. Mechanism for counting the cycles of operation of a component of a duplicating machine or the like, which mechanism is alternately operable in a first mode to count to a minimum number from a preset number and in a second mode to count the present number through successive counting sequences, said mechanism comprising:

a. manually operable selection means for presetting the number to be counted, said means including a movable selector member carrying a stop which occupies predetermined positions in response to corresponding respective numbers preset by operation of said selection means;

b. a movable indexing member mounted adjacent said selector member and including a formation adapted for abutting engagement with said stop;

c. first means on said indexing member engageable with second means adjacent the indexing member for deactuating said machine component when in response to cyclical operation of said component;

e. actuating means including said second means for initiating cyclical operation of said machine component and for substantial simultaneously disengaging said first and second means;

f. biasing means engaged with said indexing member urging the latter in a second direction opposite said first direction and thereby causing said formation to be brought into abutting relationship with said stop; and

. first and second mode control means engaged with said selector member and said indexing member such that in said first mode. the former is moved in said first direction in response to corresponding movement of said indexing member and that in said second mode the selector member remains stationary during movement of said indexing member in said first direction.

4. The mechanism according to claim 3 further defined by:

a. said selector member and said indexing member having respective surfaces in frictional engagement with each other;

b. said mode control means including restraining means engaged with said selector member; and

c. said control means also including means for varying the frictional engagement between said surfaces such that in said first mode the frictionalengagement between said indexing member and said selector member is sufficient to cause movement of the latter upon movement of the former insaid one direction and such that in said second mode the frictional engagement between said indexing member and said selector member is insufficient to cause movement of the latter upon movement of the former in said one direction.

5. The mechanism according to claim 4 wherein said means for varying the frictional engagement between said surfaces comprises spring operated means engaging one of said members for urging the same into engagement with the other of said members.

6. Mechanism for counting the cycles of operation of q a component of a duplicating machine or the like, which mechanism is alternately operable in a first mode to count to a minimum number from a preset number and in a second mode to count the preset number through successive counting sequences, said mechanism comprising:

a. manually operable selection means for presetting the number to be counted, said means including a selector wheel carrying a stop which occupies predetermined, circumferentially disposed positions in response to respective numbers preset by operation of said selection means;

. an indexing wheel mounted adjacent said selector wheel in coaxial relationship therewith and including a formation adapted for abutting engagement with said stop;

c. first means on said indexing wheel having a first surface engageable with a second surface on 9 second means mounted adjacent the indexing wheel for deactuating said machine component when said indexing wheel occupies a predetermined rotary position;

. d. indexing means engageable with said indexing wheel for indexing the latter in a first rotary direction in response to cyclical operation of said component;

e. actuating means including said second means for initiating cyclical operation of said machine component and for substantial simultaneously disengaging said first and second surfaces;

f. biasing means engaged with said indexing wheel urging the latter in a second direction opposite said first direction and thereby causing said formation to be brought into abutting relationship with said stop; and

g. first and second mode control means including restraining means engaged with said selector wheel such that in said first mode the latter is rotated in said first direction in response to corresponding rotation of said indexing wheel and that in said second mode the selector wheel remains stationary during rotation of said indexing wheel in said first direction.

7. The mechanism according to claim 6 further defined by:

a. said second means including a third surface which slidably engages said indexing wheel when said first and second surfaces are disengaged;

b. other biasing means connected with said second means for urging said third surface against said indexing wheel thereby biasing the latter axially against said selector wheel for frictional engagement therewith; and

c. said control means including means for varying the force of said other biasing means such that in said first mode the frictional engagement between said indexing wheel and said selector wheel is sufficient to overcome said restraining means and cause the selector wheel to be rotated in said first direction by corresponding rotation of the indexing wheel and that in said second mode the frictional engagement between said indexing wheel and said selec tor wheel is insufficient to overcome said restraining means whereupon the selector wheel remains stationary during rotation of said indexing wheel in said first direction.

8. The mechanism according to claim 7 wherein said restraining means includes a spring biased plunger mounted adjacent the periphery of said selector wheel, which selector wheel has peripheral detent formations engaged one at a time by said plunger.

9. The mechanism according to claim 6 further defined by:

a. said selector wheel being mounted on a shaft for rotation therewith; and

b. said selection means including a knob mounted on said shaft for rotation therewith, which knob bears circumferentially disposed numerical indicia arranged progressively from said minimum number to a maximum preset number such that the knob is rotated for advancing successively lower numbers past a fixed reference mark during rotation of said selector wheel in said first direction during said first mode of operation. 10. The mechanism according to cla1m 7 further defined by:

a. said selector wheel being mounted on a shaft for rotation therewith; and

b. said selection means including a knob mounted on defined by:

a. said first means including a recess adjacent the periphery of said indexing wheel, a face of which recess defines said first surface; and

b. said second means including a pin adapted for reception of said recess and defining said second surface. 12. The mechanism according to claim 7 further defined by:

a. said first means including a recess adjacent the periphery of said indexing wheel, one face of the recess defines said first surface; and

b. said second means including a pin adapted for reception in said recess and defining said second and third surfaces.

13. The mechanism according to claim 9 further defined by:

a. said indexing wheel being mounted on said shaft for rotation relative thereto; and

b. said biasing means including a coil spring encircling said shaft and received in a space defined by adjacent faces of said indexing and selector wheels.

14. The mechanism according to claim 6 wherein said indexing means is defined by a pawl and an annular ratchet formation, the latter being mounted on said indexing wheel. 

1. Mechanism for counting the cycles of operation of a component of a duplicating machine or the like, which mechanism is alternately operable in a first mode to count to a minimum number from a preset number and in a second mode to count the preset number through successive counting sequences, said mechanism comprising: a. indexing means including a member which is indexed in one direction of movement in response to cyclical operation of said component and which cooperates with other means to deactuate such component when said member occupies a predetermined position; b. quantity selection means including manually operated means carrying a stop for presetting any one of a quantity of numbers and for substantially simultaneously establishing corresponding respective spatial positions of said stop which is adapted to be engaged by said member for limiting movement of the latter in a direction opposite said one direction; c. means for actuating said component and for substantially simultaneously causing movement of said member in said other direction for bringing the latter into engagement with said stop; and d. mode control means connected with said selection means operable in one mode for causing movement of said stop in response to movement of said member in said one direction and operable in another mode for preventing movement of said stop during movement of said member in said one direction.
 2. The mechanism according to claim 1 further defined by: a. said selection means including an element carrying said stop and frictionally engaged by said member; b. said control means including restraining means engaged with said element; and c. said control means also including means for varying the frictional engagement between said member and said element such that in said first mode the frictional engagement between said member and said element is sufficient to cause movement of the latter upon movement of the former in said one direction and such that in said second mode the frictional engagement between said member and said element is insufficient to cause movement of the latter upon movement of the former in said one direction.
 3. Mechanism for counting the cycles of operation of a component of a duplicating machine or the like, which mechanism is alternately operable in a first mode to count to a minimum number from a preset number and in a second mode to count the present number through successive counting sequences, said mechanism comprising: a. manually operable selection means for presetting the number to be counted, said means including a movable selector member carrying a stop which occupies predetermined positions in response to corresponding respEctive numbers preset by operation of said selection means; b. a movable indexing member mounted adjacent said selector member and including a formation adapted for abutting engagement with said stop; c. first means on said indexing member engageable with second means adjacent the indexing member for deactuating said machine component when said indexing member occupies a predetermined position; d. indexing means engageable with said indexing member for indexing the latter in a first direction in response to cyclical operation of said component; e. actuating means including said second means for initiating cyclical operation of said machine component and for substantial simultaneously disengaging said first and second means; f. biasing means engaged with said indexing member urging the latter in a second direction opposite said first direction and thereby causing said formation to be brought into abutting relationship with said stop; and g. first and second mode control means engaged with said selector member and said indexing member such that in said first mode the former is moved in said first direction in response to corresponding movement of said indexing member and that in said second mode the selector member remains stationary during movement of said indexing member in said first direction.
 4. The mechanism according to claim 3 further defined by: a. said selector member and said indexing member having respective surfaces in frictional engagement with each other; b. said mode control means including restraining means engaged with said selector member; and c. said control means also including means for varying the frictional engagement between said surfaces such that in said first mode the frictional engagement between said indexing member and said selector member is sufficient to cause movement of the latter upon movement of the former in said one direction and such that in said second mode the frictional engagement between said indexing member and said selector member is insufficient to cause movement of the latter upon movement of the former in said one direction.
 5. The mechanism according to claim 4 wherein said means for varying the frictional engagement between said surfaces comprises spring operated means engaging one of said members for urging the same into engagement with the other of said members.
 6. Mechanism for counting the cycles of operation of a component of a duplicating machine or the like, which mechanism is alternately operable in a first mode to count to a minimum number from a preset number and in a second mode to count the preset number through successive counting sequences, said mechanism comprising: a. manually operable selection means for presetting the number to be counted, said means including a selector wheel carrying a stop which occupies predetermined, circumferentially disposed positions in response to respective numbers preset by operation of said selection means; b. an indexing wheel mounted adjacent said selector wheel in coaxial relationship therewith and including a formation adapted for abutting engagement with said stop; c. first means on said indexing wheel having a first surface engageable with a second surface on second means mounted adjacent the indexing wheel for deactuating said machine component when said indexing wheel occupies a predetermined rotary position; d. indexing means engageable with said indexing wheel for indexing the latter in a first rotary direction in response to cyclical operation of said component; e. actuating means including said second means for initiating cyclical operation of said machine component and for substantial simultaneously disengaging said first and second surfaces; f. biasing means engaged with said indexing wheel urging the latter in a second direction opposite said first direction and thereby causing said formation to be brought into abutting relationship with said stop; and g. first and second mode control means including restraining means engaged with said selector wheel such that in said first mode the latter is rotated in said first direction in response to corresponding rotation of said indexing wheel and that in said second mode the selector wheel remains stationary during rotation of said indexing wheel in said first direction.
 7. The mechanism according to claim 6 further defined by: a. said second means including a third surface which slidably engages said indexing wheel when said first and second surfaces are disengaged; b. other biasing means connected with said second means for urging said third surface against said indexing wheel thereby biasing the latter axially against said selector wheel for frictional engagement therewith; and c. said control means including means for varying the force of said other biasing means such that in said first mode the frictional engagement between said indexing wheel and said selector wheel is sufficient to overcome said restraining means and cause the selector wheel to be rotated in said first direction by corresponding rotation of the indexing wheel and that in said second mode the frictional engagement between said indexing wheel and said selector wheel is insufficient to overcome said restraining means whereupon the selector wheel remains stationary during rotation of said indexing wheel in said first direction.
 8. The mechanism according to claim 7 wherein said restraining means includes a spring biased plunger mounted adjacent the periphery of said selector wheel, which selector wheel has peripheral detent formations engaged one at a time by said plunger.
 9. The mechanism according to claim 6 further defined by: a. said selector wheel being mounted on a shaft for rotation therewith; and b. said selection means including a knob mounted on said shaft for rotation therewith, which knob bears circumferentially disposed numerical indicia arranged progressively from said minimum number to a maximum preset number such that the knob is rotated for advancing successively lower numbers past a fixed reference mark during rotation of said selector wheel in said first direction during said first mode of operation.
 10. The mechanism according to claim 7 further defined by: a. said selector wheel being mounted on a shaft for rotation therewith; and b. said selection means including a knob mounted on said shaft for rotation therewith, which knob bears circumferentially disposed numerical indicia arranged progressively from said minimum number to a maximum preset number such that the knob is rotated for advancing successively lower numbers past a fixed reference mark during rotation of said selector wheel in said first direction during said first mode of operation.
 11. The mechanism according to claim 6 further defined by: a. said first means including a recess adjacent the periphery of said indexing wheel, a face of which recess defines said first surface; and b. said second means including a pin adapted for reception of said recess and defining said second surface.
 12. The mechanism according to claim 7 further defined by: a. said first means including a recess adjacent the periphery of said indexing wheel, one face of the recess defines said first surface; and b. said second means including a pin adapted for reception in said recess and defining said second and third surfaces.
 13. The mechanism according to claim 9 further defined by: a. said indexing wheel being mounted on said shaft for rotation relative thereto; and b. said biasing means including a coil spring encircling said shaft and received in a space defined by adjacent faces of said indexing and selector wheels.
 14. The mechanism according to claim 6 wherein said indexing means is defined by a pawl and an annular ratchet formation, the latter being mounted on said indexing wheel. 